47
5
FUNCTIONS FOR RECEIVE
2001 NEW 2001 NEW
■ Preamp/Attenuator
The preamp amplifies received signals in the front end
circuit to improve the S/N ratio and sensitivity. Set this
to preamp 1 or preamp 2 when receiving weak signals.
The attenuator prevents a desired signal from distor-
tion when very strong signals are near the desired fre-
quency or when very strong electric fields, such as
from broadcasting stations, are near your location.
These can both set independently for each band.
➥ Push [P.AMP/ATT] several times to set the preamp
OFF, preamp 1 ON or preamp 2 ON.
•When the preamp is ON, either “P.AMP 1” or
“P.AMP 2” appears in the function display.
•When operating on the 144 MHz band, the preamp can
only be set to ON or OFF only— there is no preamp 1
and preamp 2.
➥
Push [P.AMP/ATT] for 1 sec. to set the attenuator ON.
•
“ATT” appears in the display when the function is set ON.
•Push [P.AMP/ATT] momentarily to set the attenuator OFF.
■ RIT function
The RIT (Receive Increment Tuning) function compen-
sates for off-frequencies of the communicating station.
The function shifts the receive frequency up to
±9.99 kHz in 10 Hz steps without moving the transmit
frequency.
• See #0 on p. 4 for function description.
q Push [RIT] to turn the RIT function ON and OFF.
•“RIT” and the shifting frequency appear when the func-
tion is ON.
w Rotate the [RIT/∂TX] control.
•Push [CLEAR] for 1 sec. to reset the RIT frequency.
•Push [CLEAR] momentarily to reset the RIT frequency
when the quick RIT clear function is ON. (p. 86)
•Push [RIT] for 1 sec. to add the shift frequency to the op-
erating frequency.
DD
RIT monitor function
When the RIT function is ON, pushing and holding
[XFC] allows you to monitor the operating frequency
directly (RIT is temporarily cancelled).
[P.AMP/ATT]
Push
P.AMP/ATT
Push
P.AMP/ATT
Push
P.AMP/ATT
Push for 1sec.
P.AMP/ATT
Push
P.AMP/ATT
Regular preamp, the most effective for 1.8 to
21 MHz bands without IMD corruption.
High-gain preamp, the most effective for 24
to 50 MHz bands.
Preamp activates for the VHF band
(144 to
146 MHz range; 108 to 174 for the USA version)
.
[RIT]
[CLEAR]
[RIT/∂TX] control
Appears
Regarding the use of the “P.AMP 2”
The “P.AMP 2” is a high gain receive amplifier. When the
“P.AMP 2” is used during times of strong electric fields, dis-
tortion sometimes results. In such cases, use the trans-
ceiver with the “P.AMP 1” or “P.AMP OFF” setting.
The “P.AMP 2” is most effective when:
•Used on bands above 24 MHz and when electric fields are
weak.
•Receive sensitivity is insufficient during low gain, or while
using a narrow band antenna
(such as small loop, a Bever-
age antenna or a short Yagi antenna, etc.) is used.
IC-7400.qxd 02.4.2 11:35 Page 47
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